Frequency-control system



Spt..1o, 1929. A. M. 'TROGNR 1,727,575

FREQUENCY CONTROL SYSTEM Filed Feb. 15, 1927 3 Sheets-Sheet 1 Sii/'9. :2.

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Sept. l0, 1929. A, M TRQGNER 1,727,575

FREQUENCY CONTROL SYSTEM Filed Feb. 15, 1927 3 Sheets-Sheet 3 s@ uw uw '3mm L CU f7 ryu/PM 7506056 Patented Sept. 10, j 1929.

UNITED STATES PATENT oFFlcE.

' ARTHUR M. TROGNER, OF TAKOMA. PARK, MARYLAND, ASSIGNOR T0 WIRED RADIO,

INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

FREQUENCY -CONTROL SYSTEM.

Application filed February 15, 1927. Serial No. 168,393.

My invention relates broadly to, high frequency signal transmission circuits and more particularly to a control system for effecting changes in the emitted signaling frequency by simultaneously adj ustlng the various parts of the circuits of the transmission system.

One of the objects of my invention is to provide'a frequency changing system for crystal epntrol transmitters wherein adjustments in the capacity of parts of the circuit maybe effected simultaneously with a change in the inductance of various parts of the electrical circuit. v

Another object of my invention -is to provide a system for automatically controlling the connection of a piezo electric crystal device in an oscillator circuit of a transmitter and effecting changes in the inductance and capacity values of parts'of the electrical circuits required for operation in conjunction with a piezo electric crystal element of a particular frequency.

A further object'of my invention is to provide a construction of. high frequency apparatus in which changes in the electrical constants of the circuit are effected simultaneously with' a change in the connection of a selected piezo electric crystal element in the transmitter circuits, the apparatus being arranged in compact form having relatively small physical dimensions.

Other and further objects ofmy invention reside in the construction and arrangement of parts of the frequency changing apparatus and the adjustments by which simultaneous control of the capacity and inductance f elements and selection of piezo electric crystal elements may be effected simultaneously.

My invention will be more clearly understood from the specification hereinafter following by reference to thevaccompanying drawings in which:

Figure 1 illustrates a perspective view showing the arrangement ofparts of the transmitting apparatus of my invention; Figs. 2 and 3 illustrate modified forms of condenser adjusting mechanisms which may be employed 1n the construction of frequency changing apparatus of my invention; Figs.

4 and 5 are detailed views of the adjustable pin construction, employed in the frequency changer apparatus for forming the abutting stops for the condenser mechanism in the frequency changer system; and Fig. 6 is a diagrammatic illustration of the circuit arrangement of the frequency changing apparatus of my invention.

My invention employs a rotary frequency changing switchvfor carrying a plurality of piezo electric crystal elements which are described at greater length in my copending application, Ser. No. 113.791, filed June 4, 1926, patented December 7 1926, No. 1,609,- 744. The frequency changing system by which the movement of the piezo electric crystal holder is coordinated with a change in inductance in the transmitting circuits is set forth. more particularly in my copending application 140,376, led October 8, 1926. The construction of the inductance and switch mechanism employed in the frequency changing system isset forth in my copending application 140,377, filed October 8, 1926. The circuit arrangements heretofore employed have provided for a change in the piezo electric crystal elements inthe electrical circuits of the transmitting apparatus with a simultaneouschange in the effective inductance in the circuits but have not provided for a change in the capacity-values throughout the circuit in proportion to the change in inductance. My present invention covers a frequency changing system which provides for making all adjustments with respect to the selection of piezo electric crystal elements and a change in the values of inductances and capacities simultaneously.

Fig. 1 shows schematically the arrangement of one form of this system. The multiple crystal holder 1 and the inductance changing systems 2 and 3 are controlled through the mechanism heretofore described in application 140,376, filed October 8, 1926. The variable-condensers 4, and 5 associated with the inductance systems 2 and 3 are adjusted to their required capacity values through the raqks and pinions 6 and 7, the racks 6 being held by springs 8 against the adjustable pins 9\,in the bar .1.0. There `.is a

pin 9 for each frequency position of crystal holder 1. The bar or rack 10 is moved up or down to bring the proper pins into operative relation through the rack 10 and pinion 27 under control of shaft 11 and the gear system 12. Before moving this bar 10, however, it is necessary to retract the rack pieces 6 out of the way of the pins 9. This is accomplished by turning the hand wheel 14 which operates the retractors' 15 through a suitable gearing system. This retracting system is interloeked With the frequency changing system by the member 16 and interlock wheel 17, which, is made with detent openings corresponding to the frequency positions. This retracting system can be also electrically interloclied with the power supply as at 18 so that the frequency changing y system cannot be inadvertently operated while the power is connected.

I have represented a duplicate series of apparatus units corresponding to the apparaactuates the rack 6 to which the crank arm 21 lThe carrier 23 is rotatably mounted on shaft member 25, the rotation of which may be coordinated With the control 19. In 1ieu`of the rotatable carrier a longitudinal rack member 10 may be operated in coordination with the crank 21 as represented in Fig. 3. In this case the arm 22 of the crank 21 abuts againstthe ends of screw threaded pins 9 and limits the movement of the rack 6,' which in turn -controls the adjustment of the variable condensers. Variable condenser 4 has its rotor plates driven through a pinion 7, which en.- gages with rack 6 for controlling the spacial relation of the rotor plates with respect to the stator plates. In order to insure the accurate positioning of the pins 9 in a selected position, I may provide locking pins 26 adj acent the screw threaded pins 9 by which the pins 9 are free to slide in and out but are prevented from rotating in the rack 10. The interiorly threaded adjusting nuts 24 move thepins to desired positions. The adjustment is therefore self-locking.

In actuating the rotatable carrier 23 of Fig. 2 the shaft member 25 may be connected to the shaft 11 under control of the adjusting handle 19. Similarly, in Fig. 3 the rack 10 is driven from shaft 11 by means of pinion 27.

The operation of the system will be understood by a consideration of the sequence of steps as follows: First, turn wheel 14 to retract all condenser adjusting mechanisms and unlock frequency changing system; second, turnwheel 19 to desired frequency position; third, turn Wheel 14 back, locking the system and allowing the condenser adjusting mechanism to assume the desired positions as determined by the appropriate pins 9. If there are any variations in circuit constants such are due to temperature or humidity conditions which must be, compensated for, this can be readily accomplished by moving the appropriate pins 9 in or out by means of their:

associated knurled wheels. Such a change in position of a pin 9 for one frequency does not affect the adjustment of any other frequency.

In Fig. 6 I have illustrated the connections of the inductanceand capacity systems under control of the hand Wheel 19 illustrating the piezo electric crystal holder 1 connected to the central shaft member 28 for inserting a select ed piezo electric crystal in the input circuit of electron tube oscillatorl 29. Arranged to move with the shaft 28 I have illustrated a rotatable carrier 23 as represented in Fig. 2

having adjustable pins 9 projecting radially therefrom for contacting with the limiting mechanical movement 22 and controlling the position to which condenser 4 may be adjusted. Similarly, the inductance switch 2 may be controlled through the rotatable members 29 and 30 to a selected position for the transfer of high frequency oscillating current to the inputcircuit of the power amplifier 31. 'Ihe output circuit of the power amplifier 31 is coupled to the antenna l circuit 32-33 through inductance system 28 and sets of position adjusting mechanisms may be provided for simultaneous` rotatable movement. I have illustrated at 23 and 22 the mechanism for controlling the position of the plates of the condenser 5. At 29 and 30 I have represented, th'e mechanism for controlling the adjustment of inductance and capacity in the transmitter circuits and the selection of a piezo electric crystal of particularfrequency characteristic for the control of the transmitter at that frequency 4for which the values of inductance and capacity have been selected.

I have illustrated the coordination of the several tuning mechanisms ina number of preferred embodiments, but I desire that it be understood that modifications may be made and that no limitations upon my invention are intended other than are imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A tuning system for high frequency circuits comprising a plurality of adjustable timing elements, a main control for actuating said elements, means for locking said main control against operation, a vertically .adjustable bar member and a plurality of adjustable stops carried by said bar member for limiting the movement of said elements upon operation of said main control in a predetermined manner and maintaining said tuning elements in selected settings While said main control is in locked condition.

2. Tuning apparatus comprising a plurality of circuit elements each arranged to be adjusted to selected positions in an electrical circuit'for selectively setting the operating frequency thereof, a main control for affecting simultaneous movement of each of said circuit elements a bar member extending longitudinally with respect to said circuit elements, a plurality of stops carried by said,

bar member for automatically limiting the setting of said circuit elements for adjusting said elements in proportion in cooperative relation for a particular frequencyyand means for locking said circuit elements in a selected.

position.

3. Tuning apparatus comprising a plurality of adjustable circuit elements, a main control for effecting movement of said circuit elements to selected positions and a plurality of adjustable stops carried by a longitudinally extending member and sliiftable longitudinally in position in proportion to the `movement of said main control for limiting the movement of said adjustable circuit elements for selectively limiting said adjustable circuit elements for operation at predetermined frequencies.

4. An electrical tuning system comprising a plurality of variable tuning elements each having rotatable means for controlling the setting thereof, a main control member, means interlinking said main control member with each of said rotatable means for effecting a proportional movement of each of said variable tuning elements, longitudinally extending bar adjacent each of said tuning elements and a plurality of limiting stops carried by said longitudinally extending bar and sliiftable in position in accordance with the movement of saidgnain control for selectively .limiting the setting of selected ones of said 'said main control member.

5. High frequency apparatus for cont-rolling the adjustment of a plurality of electrical circuits comprising a plurality of independent tuning elements each rotatable in selected positions for adjusting said circuits for operation at predetermined frequencies, a multiple piezo electric crystal holder carrying a plurality of piezo electric crystals ground to different selected frequencies, means interlinking each of said tuning elements and saidcrystal holder, a main control for actuating said means for-imparting movement to said piezo electric crystal holder and each of said independent tuning elements, a device projectible into the path of said main cont-rol for preventing operation thereof, a ro`d member carrying a plurality of limiting stops shiftable longitudinally to positions adjacent selected ones of said tuning elements for automatically limiting the movement of said tuning elements to predetermined set- ,tings under operation of said maincontrol, selected onesot said tuning element being independently controllable upon the retraction of said device.

6. Tuning apparatus comprising a plurality of variable tuning elements each having variable adjusting means associated therewith, La ypiezo electric crystal holder having a plurality of crystal elements of different frequency characteristics carried thereby, a main control, means interlinkingsaid main control With said piezo electric crystal hold ci' and each of said variable tuning elements, an independent control interlinked with said piezo electric crystal holder and selected ones of` said tuning elements, said main control being operative subsequent to the operation of said independent control and a plurality of limiting stops shiftable in position in accordance With the movement of said main control for limiting the movement of selected ones of said variable tuning elements under actuation ofisaid main control.

7. Tuning apparatus comprising a plurality of variable tuning elements each having variable adjusting means associated therewith, a piezo electric crystal holder having a j plurality of crystfal elements of different frequency characteristics carried thereby, a main control, a device normally projecting into the path of rotation of said main control for maintaining a particular setting thereof, means interlinking said main control With said piezo electric crystal holder and each of said variable tuning elements, a meniber shiftable longitudinally in proportion to the `movement of said main control, a plurality of adjustable stops carried by said meinber for providing abutments to the movement of selectedones of said timing elements ,beyond vpredetermined positions under acretractable from the path of said main control for permitting adjustment of said tuning elements.

8. A high frequency tuningsystem for a plurality of electron tube circuits including a plurality of coupled systems including inductance and capacity elements interconnecting the circuits of the electron tubes, a piezo electric crystal vfrequency controlling apparatus, a main controlling shaft for shifting the position of said piezo electric crystal frequency controlling apparatus, locking means for normally preventing a shift in movement of said apparatus, means for retracting said locking means with respect to said apparatus, means actuated vby a change in position of said piezo electric `crystal frequency controlling apparatus for eifecting predetermined changes in the values of said inductance and capacit-y elements in saidlcoupled systems, and limiting stops simultaneously actuated by movement of said main controlling shaft forproviding abutments preventing the adj ustment of inductance and capacity elements beyond a predetermined setting during the unlocked condition of said firstmentioned means. Y

9. A high frequency tuning system for a plurality of electron tube circuits including a plurality of coupled systems including inductance and capacity elements interconnecting the circuits of the electron tubes, a piezo electric crystalfrequency controlling apparatus, a main controlling shaft for shifting the position of said piezo electric crystal frequency controlling apparatus, means for normally locking said main controlling shaft against rotation, said means being retractable for permitting actuation of said main controllmg shaft, means actuated by a change in position of said piezo electric crystal frequency controlling kapparatus for effecting predetermined changes in the values of said inductance and capacity elements in said coupled systems, a longitudinally extending bar member, a-plurality of independently adjustable screw threaded pin members carried by said bar member, said member being shiftable into position adjacent said Ainductance and capaclty elements and" actuated by the movement of said'main controlling shaft for providing abutments for limiting the adjustmentof said1 elements to predetermined positions subsequent to the retraction of said first mentioned means.

10. A high frequency'tuning and frequency control system comprising a plurality of adjustable tuning units and a piezo electric -cry'stal control apparatus each arranged to be moved to selected adjusting positions, a mechanical adjusting system, means operative by said mechanical adjusting system for moving` selected ones ofsaid tuning units to predetermined positions, and simultaneously shifting said piezo electric crystal control apparatus to a corresponding position, and an electrical circuit closer controllable by operation of said mechanical adjusting system for de-energizing said tuning units during the intervals of adjustment of said tuning units and said piezo electric crystal control apparatus.

11. A high frequency tuning system having a plurality of electron tube circuits includingr a plurality of coupling systems each having inductance and capacity elements interconnecting the circuits of the electron tubes, a piezo electric crystal frequency controlling apparatus, a main control shaft for shifting the position of said piezo electric crystal frequency controlling apparatus, locking means for said control shaft` and independent means for simultaneously deenergizing the circuit through said inductance and capacity elements and releasing said locking means for imparting movement to said inductance and capacity elements through said main control to predetermined positions for selectively fixing said circuits for operation at a definite frequency corresponding to the frequency setting of said piezo electric crystal frequency controlling apparatus.

ARTHUR M. TROGNER. 

